Among the various technology incorporated into an HVAC unit, ignition components that fire up the burners in a gas furnace are among the most critical. Electric furnaces utilize electrical heating elements that produce warmth. However, gas heating requires a fail-safe method to ignite the gas that produces the flame that generates the heat. In today’s gas furnaces, two types are most common: a standing pilot light and electronic ignition. Here’s how the two methods differ.
- Pilot light HVAC ignition. The pilot light is a small gas flame that burns continuously as long as the furnace is turned on and operating. When the home thermostat signals for heat, the electrically operated gas valve opens and natural gas flows into the burners. The pilot flame, situated near the burners, ignites the flow of gas, and the burners begin generating heat. When the thermostat temperature setting is achieved, the burner gas valve turns off.
- Electronic HVAC ignition. Electronic HVAC ignition incorporates a solid-state “hot surface” igniter. When the thermostat signals for warmth and opens the main gas valve, the electronic igniter instantly turns red hot and ignites the gas flow. If the burner flame goes out for any reason, an electronic flame sensor automatically shuts off the flow of gas to the furnace for safety.
Pilot vs. Electronic HVAC Ignition
Pilot lights have been utilized for more than a century and have a time-tested record of service. However, there’s a downside: A pilot burns continuously, typically consuming about 600 to 800 BTUs of gas every 24 hours. While this added expense is not terribly excessive, monthly gas-utility bills are rising all the time.
Electronic ignition is now the accepted standard for safety and reliability in gas furnaces. The device consumes no gas and uses only a momentary burst of electrical power when the igniter actuates. On the minus side, an electronic igniter is susceptible to wear and tear after many years. Mainly, this is expansion and contraction, causing the igniter to crack and require replacement.
For more information about gas and electric furnace pilot lights for safe, dependable HVAC ignition, talk to the heating pros at Jackson & Sons.